1. Field of the Invention
The invention relates to a timing controller, a liquid crystal display device and a method for driving the LCD device, specifically relates to a timing controller used in the liquid crystal display device and a method for driving the liquid crystal display having the timing controller.
2. Description of the Related Art
A general liquid crystal display device includes a plurality of pixels, each of which includes three sub-pixels having three primary colors, such as Red (R), Green (G) and Blue (B), respectively, in order to display multiple colors. The information as to the color to be displayed is transformed into a gradation signal of R, G and B in response to a luminance signal and a color-difference signal, and the gradation signal is then inputted to a timing controller. The gradation signal sent to the timing controller is sorted in order to display the image at a display panel, and the sorted gradation signal is sent to a driver, which is disposed on the display panel, for driving the display panel. The timing controller also generates other timing data necessary to display the image at the display panel.
Basically, displaying a specific color is performed by a combination of the three primary colors, which are R, G and B. Thus, the scope of the color to be displayed in accordance with the combination of the three primary colors is limited within a scope of the triangle (color-reproduction <color-space> area) as shown in FIG. 6 whose vertexes are R, G and B, respectively, However, in order to display the highly-pure color, it is necessary to add complementary colors, such as Yellow (Y) as shown in FIG. 7 and the others.
According to the Japanese laid open patent publication JP 2006-317899A, it is disclosed that a conventional liquid crystal display device includes a liquid crystal panel having 4-color sub-pixels, a data driver providing video data signals to each sub-pixel, a gate driver 106 providing a scan pulse to each sub-pixel, a data converter generating a gain value by analyzing a ratio of an achromatic color signal to a chromatic color signal of 3-color source data inputted from an external source and converting the 3-color source data into 4-color data using the generated gain value and a timing controller providing the 4-color data received from the data converter to the data driver and controlling the gate driver and the data driver.
However, according to the conventional liquid crystal display device described in the reference, since the 4-color data having the complementary color data are generated in the data converter, which is disposed in the previous stage of (in the upstream of) the timing controller, the large encumbrance hangs to the liquid crystal display device as a whole.
When a general liquid crystal display device displays a specific color image, three primary colors of R, G, and B are used for the processes for displaying the image, which are performed by a color imaging device, such as CCDs (Charge Couple devices) or CMOSs (Complementary Metal Oxide Devices). By adding the complementary color data on the 3-color data, the load for the processors in the liquid crystal display device or connection cables is increased.
When the general liquid crystal display device employs the technology disclosed in the reference, the following problems may occur. FIG. 8 is a conceptual diagram of a liquid crystal display device in the related art, which employs the technology disclosed in the reference.
The liquid crystal display device 200 includes a graphic processor 220 in which the data converter 221 disclosed in the reference is incorporated. The complementary color data (the Y data) is generated in the graphic processor 220 so that the load for the graphic processor 220 or a connection cable between the graphic processor 220 and a timing controller 230 is increased because the complementary color data (the Y data) is added. For example, when the Y data is added as the complementary color data, the volume of the data processed in the graphic processor 220 is increased by four thirds (4/3), and this increased volume of the data increases the load of the LSIs and the cables used in the liquid crystal display device 200.
In the liquid crystal display device 200, the R data, the G data, the B data and the Y data are generated in the graphic processor 220, and all data are transmitted to the timing controller 230 in the form of a low amplitude differential signal. Such data are generally transmitted by LVDS (Low Voltage Differential Signaling) system (or other Internal Panel Interface). In the case that 3 color data (the R data, the G data and the B data) are used, twenty four (24) signal lines (=12 lines×2) are required under the condition that the each of the data has 10 bits and clock signals are divided by odd and even. However, when the Y data are added, around thirty (30) through thirty two (32) signal lines are required. Otherwise, the data transmitting frequency should be increased by four thirds (4/3).